Film-Tech Forum ARCHIVE: Kollmorgen reversable anamorphic lens ?

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Posted by Alan Gouger (Member # 543) on 06-30-2005, 03:07 PM:

Ok dumb question time.
What would you use one of these for.
I see these on Ebay once in a while and can never figure out a use for it.

[ 01-20-2010, 10:06 AM: Message edited by: Mike Olpin ]

Posted by Mitchell Dvoskin (Member # 751) on 06-30-2005, 03:10 PM:

Reversible Anamorphic lenses are for theatres that need to shrink the top/bottom rather than expand the sides to uncompress the anamorphic squeeze.

Posted by John Walsh (Member # 168) on 06-30-2005, 03:23 PM:

Yep, just what Mitchell said. They were usually used at drive-ins because of the long throws. If you needed a 9 inch focal length lens (not too common) you'd put the adapter in the 'reverse' direction, and attach a more commonly available 4.5 inch lens.

Posted by Alan Gouger (Member # 543) on 06-30-2005, 03:50 PM:

I think I understand so it is still giving you a scope ratio but maintaining the original width. That makes sense.

Posted by Steve Guttag (Member # 268) on 06-30-2005, 04:02 PM:

Actually...one needs to know the Kollmorgen lens line a bit...the lens shown there is a prime lens of about 6" and the KA-299 anamorphic. In the configuration shown...it is actually working like a normal anamorphic...if it was oriented like a conventional anamorphic of today, it would be working as a reverse.

This was Kollmorgen's answer for a 4" anamorphic lens since 4" primes worked with it. Since in a drive-in one would want long lenses, a reverse anamorphic with a large exit would be normal. So, one could have a 6" prime with the KA-299 and have an EF of 12" yet not be constrained by the light of a little 2-25/32 lens diameter.

The lens has two sets of distance markings. The "Ordinary" lines are in red and the "reversed" lines are in black.

Posted by Mark Gulbrandsen (Member # 72) on 06-30-2005, 07:53 PM:

The KA299 was also never a lens that had even decent resolutuion. If that was a Schneider or ISCO reverse anamorphic then you could actually obtain superior resolution over using a standard a 2X anamorphic under the right conditions because there is less squeeze (unsqueeze or anamorphic gain) ground into the lens. The result is less barrel distortion and alot less residual astigmatism.

Mark

Posted by Tim Reed (Member # 137) on 06-30-2005, 08:32 PM:

What Steve said. This particular attachment is "built" in the reverse direction.

Posted by Steve Guttag (Member # 268) on 07-01-2005, 05:41 AM:

That lens was not actually built by Kollmorgen but by Kasaka of Japan. It and the KA298 were the beginnings of Kollmorgen and eventually Schneider's less than thrilling anamorphics.

Posted by System Notices (Member # 2357) on 01-19-2010, 10:18 PM:

It has been 1663 days since the last post.

Posted by Xavian-Anderson Macpherson (Member # 5571) on 01-19-2010, 10:18 PM:

My apologies to everyone who reads this. I know this is a very old thread. But I need information desperately. I just received one of these today from eBay. I had the crazy idea that maybe the Kollmorgen could be converted. At least, I wanted to play around with it. I have the large 4" 101.6mm KA299. I'm not interested in using it for anything else other than experimentation. So I want to know how to take the thing apart. It seems some of you here are very experienced with this lens. So I hope someone will respond to this and answer my questions.

If I should have started a new post, let me know.

Xavian-Anderson Macpherson
ShingoshiDao

Posted by Sean McKinnon (Member # 612) on 01-20-2010, 10:53 AM:

I was installing a drive-in one time and the reverse anamorphic was damaged in shipment and there was no way to get it replaced in time for the advertized opening. However, there was an old regular anamorphic laying around from some used equipment that was purchased. We fashioned a piece of sheet metal and pipe collars to hold the anamorphic onto the front of the century sa backwards and installed the prime lens in the regular lens collar.

Now I know what you must be saying but beleive it or not once everything was aligned it actually looked decent. A lot better than I thought it would. I figured it would barely get them through as not opening was not an option (the owners entire life savings was invested in this project) but it actually worked out well.

Now the good thing was both films being shown for this double feature were scope so they did not have to take the lens off.

I wouldn't beleive it if I hadn't done it myself! [Wink]

Posted by Tony Bandiera Jr (Member # 2365) on 01-20-2010, 12:58 PM:

Sean, I have done a similar "Rube Goldberg" thing to get an integrated 16mm anamorphic to fit my Kinotons...I wrapped the barrel of the lens with scrap film to make it fit in the holder!!

It worked quite well.

I now have the machine shop equipment to fabricate a proper aluminum adapter collar.

Posted by Mark Gulbrandsen (Member # 72) on 01-20-2010, 01:02 PM:

Dismantling a B&L scope lens is detailed below and the Kollmorgen may be the same...

To disnmantle a B&L lens unscrew the front locking ring all the way. Then unscrew the focus ring in the opposite direction until it falls off. Under that you'll find slots with dogs in them. Loosen the screws in those dogs and the front element group can be pulled out in it's metal tube. Rermoving the lenses will require special spanner wrenches tor emove the actual threaded rings holding those in. Those spanner wrenches are very hard to find and you may have to make your own.

Hope this helps...
Mark

Posted by Xavian-Anderson Macpherson (Member # 5571) on 01-20-2010, 06:11 PM:

Is the same thing true for the Kollmorgen-Kosaka KA299? I had to soak the threads overnight in WD-40 to get the locking collar to move. Once I did that, I was indeed able to remove it. The focusing ring took a bit longer to get free. But it seems to stop at the bottom of it's adjustment. I will have to try this again, and see if it applies. But if the lenses are different, the Kollmorgen may not disassemble the same way.

When looking inside of the lens, I could see the dogs you mentioned here. There's an independently rotating ring for the scale which moves somewhat freely. But the focusing ring does not come off. I suspected that it should. So I'm happy to hear that my assumption was correct.

I will be supplying photos of the lens as I advance through this.

Xavian-Anderson Macpherson
ShingoshiDao

Posted by Xavian-Anderson Macpherson (Member # 5571) on 01-21-2010, 06:33 AM:

Xavian-Anderson Macpherson
needs to read the rules and FAQ.

[ 01-21-2010, 12:09 PM: Message edited by: Mike Olpin ]

Posted by Steve Guttag (Member # 268) on 01-21-2010, 09:04 AM:

Hmmm...anyone want to put a stop-watch on when the post above gets "fixed?"

Two things...if you have a question regarding the rules...you should direct them to the moderators for an explanation. Second, linking to pictures off-site is also against the rules (as the links you provided will eventually go away and thus your post will make make no sense without the pictures.

Steve

Posted by Steve Guttag (Member # 268) on 01-21-2010, 12:00 PM:

Wow...it must be a moderator holiday!

Posted by Mike Olpin (Member # 1115) on 01-21-2010, 12:09 PM:

We all get busy, Steve. [Smile]

Posted by Mark Gulbrandsen (Member # 72) on 01-21-2010, 06:36 PM:

Oh, Did they get internet brought into Traverse City now....?

Posted by Xavian-Anderson Macpherson (Member # 5571) on 01-21-2010, 07:57 PM:

Gee! I'm sorry. I thought I was in the right place asking the right questions. In other forums I've had others complain about not updating previous posts instead of starting new ones. With so many forums with different rules, it's difficult to keep track of who wants what where.

Xavian-Anderson Macpherson
ShingoshiDao

Posted by John Wilson (Member # 269) on 01-21-2010, 09:00 PM:

Your questions are right...just don't link to any photos off-site...download them to your computer and upload them here. (see Steve's reasoning for this important rule).

For text, it's OK to link (link away) but the text is to be copied and pasted here for the future.

Posted by Steve Guttag (Member # 268) on 01-22-2010, 09:07 AM:

Also, when one questions the rules...it is best to email those that made the rules as to their purpose rather than openly questioning them in the forum.

Steve

Posted by Monte L Fullmer (Member # 2797) on 01-23-2010, 12:28 AM:

quote: Steve Guttag
(as the links you provided will eventually go away and thus your post will make make no sense without the pictures.

..lot of your automotive forums are like this - allowing off sites to post picts. Then when you do a research on a old post for some pict info, that link is long dead and dead info. (sorry, to drift off topic a bit there...)

Posted by Xavian-Anderson Macpherson (Member # 5571) on 02-19-2010, 03:26 AM:

I finally got around to taking the Kollmorgen apart. I've cleaned the residue from interior surfaces of the lenses. However, there are still too many scratches on the outside surfaces. I'm not sure yet if or how I may be able to use this lens in such a way that the imperfections are able to be productive in the images created with it. I'm still considering my alternatives. I think I remember there being a fluid that could be applied to reduce the appearance of scratches. But I don't remember what the product was. It would be better than having to deal with scratches which couldn't otherwise be removed.

One thing that I've thought of is adding a wide-angle converter to the front of the lens, which would reduce the size of the scratches relative to the image.

Another thing that I would like to know is whether or not the two separate groups (front and rear) can be remounted (maybe in a newly modified body) to allow them to be repositioned closer together in relationship to each other? I'm wondering how much of a wider angle-of-view can be obtained by doing that? I'm pretty certain that the closer the groups are to each other, the less vignetting would be encountered in the final result. If anyone here has specific knowledge about this, I would like to hear what you have to offer.

Thanks,
Xavian-Anderson Macpherson
ShingoshiDao

Posted by Xavian-Anderson Macpherson (Member # 5571) on 03-04-2010, 11:55 PM:

I just purchased a Bausch & Lomb 2X anamorphic lens. I haven't yet received it. But I would like to know a few things beforehand.

1.) What is the exact size of the thread on these lenses? I need to know the pitch as well.
2.) What are some of the projector lenses this would work with? I would like to see if I can find any on eBay.
3.) Can I get a filter adapter that will allow me to attach another lens behind or in front of it? Like a 77mm to ?? step-up adapter.
4.) Are the groups inside this lens the same diameter? The Kollmorgen seemed to have the same size for both front and rear groups, leading me to think they can be remounted in a much shorter barrel.
5.) Is it possible to remount both the front and rear groups in another barrel, so as to minimize the distance between them? I think that would eliminate having to have the anamorphic "focused" to match the working lens.

As far as the front of the lens goes, I can always use a clamp-on filter mount. But the back of the lens is my immediate concern right now. I'm wondering if the lens truly is 4", does Tiffen or others make an adapter to accept 4" series filters in the front of other lenses? Due to the weight of this lens, I already know that I will have to mount it to my tripod, and let everything that is lighter than it hang off this lens. In the case that other components as nearly as heavy as the anamorphic, I will simply have to brace them as well.

But the best case scenario for me would be to remount the groups into a much shorter and therefore lighter more manageable barrel with 105mm threads on front and back. Because 105mm filter thread is relatively common. What I want is something that functions like the Schneider Cine-Digitar lenses. Schneider in fact makes several anamorphic lens that can easily be used as photographic accessories. But their compression ration is mostly limited to 1.33:1. Having the groups of the Bausch remounted will give me a 2X compression, with a much wider angle-of-view and likely no vignetting with shorter focal length lenses. Being able to shoot with a wide-angle lens through the Bausch is what I most want to do.

So please step and give some feedback here.

Thanks,
Xavian-Anderson Macpherson
ShingoshiDao